Life’s ingredients discovered in samples Nasa probe returned from an asteroid

Samples returned from an asteroid contain a surprising abundance of the basic ingredients of life. They were discovered to be rich in carbon, nitrogen and ammonia, with over 30 kinds of amino acids and the five nucleobases found in RNA and DNA.¹ The asteroid, Bennu, was targeted by a Nasa mission that returned a capsule to Earth in September 2023.

Bennu is about 500m in diameter and is a loosely bound accumulation of boulders, gravel and dust. It is barely held together by its own gravity. ‘Its surface is darker than coal, so we intuited that it would be rich in organic materials since carbon is known to make materials dark,’ says Dante Lauretta, a planetary scientist at the University of Arizona, who led the Osiris-Rex asteroid return mission to Bennu that launched in 2016.